The secret technology that powers Xbox 360's Project Natal lollipop-free motion controls actually isn't leprechauns, as we initially suspected. The guts are made by a little company called PrimeSense.
Microsoft built Project Natal around a reference design made by PrimeSense, called PrimeSensor. It's essentially three components: a CMOS image sensor, an infrared light source, and PrimeSense's PS1080 system-on-a-chip.
The PS1080 SoC is the brains of the operation, controlling the IR projector that blankets the room with an IR Light Coding image. The CMOS image sensor picks up the projected IR light, and passes the IR image to the PS1080 chip, where it's processed so Project Natal sees the room in 3D (it can see depth, that is—that yellow picture up top is a depth map). Microsoft adds a second, optional color camera, which PrimeSense's chip matches up with pixel by pixel to the depth image the infrared camera sees. And then everything is pushed to the Xbox via USB 2.0.
True, we learned when we first saw Project Natal it could see in the dark by using IR, but now all the magic is really gone. No more secrets. It's sad, because I kind of like secrets. Usually. [PrimeSense via BusinessWire]